Description of a prototype combined CT-SPECT system with a single CdZnTe detector

• Published in: 2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149) Vol. 3; pp. 16/1 - 16/5 vol.3
• Main Authors: Iwata, K., Soo-Il Kwon, Hasegawa, B.H., Bennett, P.R., Cirignano, L., Shah, K.S.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 2000
• Subjects: Anodes; Computed tomography; Energy resolution; Imaging phantoms; Prototypes; Pulse shaping methods; Sensor arrays; Spatial resolution; X-ray detection; X-ray detectors
• ISBN: 9780780365032; 0780365038
• ISSN: 1082-3654; 2577-0829
• DOI: 10.1109/NSSMIC.2000.949158

The authors have developed a system that performs both X-ray CT and SPECT using a single CdZnTe detector. Their prototype employs a 9.6/spl times/9.6-mm/sup 2/ CdZnTe detector with 1.5/spl times/1.5-mm/sup 2/ pixellated anodes configured as a 4/spl times/4 array. Pulse counting electronics with short shaping time (50 ns) are used to satisfy requirements for high photon rates in X-ray imaging, and to achieve response linearity up to 4/spl times/10/sup 5/ counts per second per detector element. The measured energy resolution at 140 keV is 10.4%. The authors have characterized system performance by imaging a radiographic resolution phantom and the Hoffman Brain phantom. The spatial resolutions of CT and SPECT are about 1 mm and 9 mm, respectively. The sensitivity per detector area of radionuclide imaging is about one-half of that of a conventional imager. The registration of images from these two modalities is intrinsic since the imaging geometry is identical.